Back to EveryPatent.com
United States Patent | 5,282,245 |
Anderson | January 25, 1994 |
A bi-directional noise-cancelling microphone comprising a detector for detecting acoustical signals centrally positioned within a tubular member that has flared entries. The microphone provides a bi-polar response pattern, and effectively cancels unwanted noise incident upon the microphone at the sides of the tubular member, as well as noise above a particular frequency dictated by the length of the tubular member. By providing flared entries to the tube, the maximum peak response frequency of the microphone is extended up to 40% higher than that achieved with a similar tubular member with non-flared entries. An embodiment of the tubular bi-directional microphone with flared entries is disclosed wherein the microphone is provided with a two-stage pop filter system. The pop filter system includes a first screen covering the front entry of the microphone housing. A second screen is constructed so as to vent the first screen, thereby preventing pop signals from being produced.
Inventors: | Anderson; Carl R. (Wilmette, IL) |
Assignee: | Shure Brothers, Incorporated (Evanston, IL) |
Appl. No.: | 861924 |
Filed: | April 1, 1992 |
Current U.S. Class: | 379/433.03; 381/163; 381/356; 381/357 |
Intern'l Class: | H04M 001/00; H04R 025/00 |
Field of Search: | 379/433 381/150,155,156,157,158,154,168,169,188,183,187 455/89,90 |
1235510 | Jul., 1917 | Tigerstedt | 381/157. |
2627932 | Feb., 1953 | Volkmann et al. | 381/169. |
2790164 | Apr., 1957 | Oberg | 381/156. |
3585317 | Jun., 1971 | Dvorsky | 381/155. |
4009355 | Feb., 1977 | Poradowski | 381/155. |
4232205 | Nov., 1980 | Ribeyre | 381/169. |
4768614 | Sep., 1988 | Case | 381/169. |
4817163 | Mar., 1989 | Stastny | 381/150. |